Performance of voice and video conferencing over ATM and gigabit ethernet backbone networks

Gigabit Ethernet and ATM network technologies have been modeled as campus network backbones for the simulation-based comparison of their performance. Real-time voice and video conferencing traffic is used to compare the performance of both backbone technologies in terms of response times and packet end-to-end delays. Simulation results show that Gigabit Ethernet has been able to perform the same and in some cases better than ATM as a backbone network for video and voice conferencing providing network designers with a cheaper solution to meet the growing needs of bandwidth-hungry applications in a campus environment

The use of Ethernet in the DataFlow of the ATLAS Trigger & DAQ

The article analyzes a proposed network topology for the ATLAS DAQ DataFlow, and identifies the Ethernet features required for a proper operation of the network: MAC address table size, switch performance in terms of throughput and latency, the use of Flow Control, Virtual LANs and Quality of Service. We investigate these features on some Ethernet switches, and conclude on their usefulness for the ATLAS DataFlow network.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, March 2003, 10 pages, LaTeX, 10 eps figures. PSN MOGT01

Full-Service MAC Protocol for Metro-Reach GPONs

“This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder." “Copyright IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.”An advanced medium access control protocol is presented demonstrating dynamic bandwidth allocation for long-reach gigabit-capable passive optical networks (GPONs). The protocol enables the optical line terminal to overlap the idle time slots in each packet transmission cycle with a virtual polling cycle to increase the effective transmission bandwidth. Contrasting the new scheme with developed algorithms, network modeling has exhibited significant improvement in channel throughput, mean packet delay, and packet loss rate in the presence of class-of-service and service-level differentiation. In particular, the displayed 34% increase in the overall channel throughput and 30 times reduction in mean packet delay for service-level 1 and service-level 2 optical network units (ONUs) at accustomed 50% ONU load constitutes the highest extended-reach GPON performance reported up to date.Peer reviewe

Ethernet - a survey on its fields of application

During the last decades, Ethernet progressively became the most widely used local area networking (LAN) technology. Apart from LAN installations, Ethernet became also attractive for many other fields of application, ranging from industry to avionics, telecommunication, and multimedia. The expanded application of this technology is mainly due to its significant assets like reduced cost, backward-compatibility, flexibility, and expandability. However, this new trend raises some problems concerning the services of the protocol and the requirements for each application. Therefore, specific adaptations prove essential to integrate this communication technology in each field of application. Our primary objective is to show how Ethernet has been enhanced to comply with the specific requirements of several application fields, particularly in transport, embedded and multimedia contexts. The paper first describes the common Ethernet LAN technology and highlights its main features. It reviews the most important specific Ethernet versions with respect to each application field’s requirements. Finally, we compare these different fields of application and we particularly focus on the fundamental concepts and the quality of service capabilities of each proposal

Efficient T-CONT-agnostic Bandwidth and Wavelength Allocation for NG-PON2

Dynamic bandwidth and wavelength allocation are used to demonstrate high quality of service (QoS) in time wavelength-division multiplexed–passive optical networks (TWDM-PONs). Both bandwidth and wavelength assignment are performed on the basis of transmission containers (T-CONTs) and therefore by means of upstream service priority traffic flows. Our medium access control (MAC) protocol therefore ensures consistency in processing alike classes of service across all optical network units (ONUs) in agreement with their QoS figures. For evaluation of the MAC protocol performance, a simulator has been implemented in OPNET featuring a 40 km, 40 Gbps TWDM-PON with four stacked wavelengths at 10 Gbps each and 256 ONUs. Simulation results have confirmed the efficiency of allocating bandwidth to each wavelength and the significant increase of network traffic flow due to adaptive polling from 9.04 to 9.74 Gbps. The benefit of T-CONT-centric allocation has also been measured with respect to packet delay and queue occupancy, achieving low packet delay across all T-CONTs. Therefore, improved NG-PON2 performance and greater efficiency are obtained in this first demonstration of T-CONTs allocated to both wavelength and time.Peer reviewe

High-Speed Communications Over Polymer Optical Fibers for In-Building Cabling and Home Networking

This paper focuses on high-speed cabling using polymer optical fibers (POF) in home networking. In particular, we report about the results obtained in the POF-ALL European Project, which is relevant to the Sixth Framework Program, and after two years of the European Project POF-PLUS, which is relevant to the Seventh Framework Program, focusing on their research activities about the use of poly-metyl-metha-acrilate step-index optical fibers for home applications. In particular, for that which concerns POF-ALL, we will describe eight-level pulse amplitude modulation (8-PAM) and orthogonal frequency-division multiplexing (OFDM) approaches for 100-Mb/s transmission over a target distance of 300 m, while for that which concerns POF-PLUS, we will describe a fully digital and a mixed analog-digital solution, both based on intensity modulation direct detection, for transmitting 1 Gb/s over a target distance of 50 m. The ultimate experimental results from the POF-ALL project will be given, while for POF-PLUS, which is still ongoing, we will only show our most recent preliminary results

Distributed PC Based Routers: Bottleneck Analysis and Architecture Proposal

Recent research in the different functional areas of modern routers have made proposals that can greatly increase the efficiency of these machines. Most of these proposals can be implemented quickly and often efficiently in software. We wish to use personal computers as forwarders in a network to utilize the advances made by researchers. We therefore examine the ability of a personal computer to act as a router. We analyze the performance of a single general purpose computer and show that I/O is the primary bottleneck. We then study the performance of distributed router composed of multiple general purpose computers. We study the performance of a star topology and through experimental results we show that although its performance is good, it lacks flexibility in its design. We compare it with a multistage architecture. We conclude with a proposal for an architecture that provides us with a forwarder that is both flexible and scalable.© IEE